"We welcome your interest in the Tampa Bay area and the potential for expanded use of new innovative technologies in transportation services," reads a letter sent Friday to the San Francisco-based ride-sharing service by the interim executive director of the Public Transportation Commission.

But Kevin Jackson continued: The PTC has the final word.

Similar to other ride-sharing services, Lyft uses a smartphone application to connect passengers with drivers who use their personal vehicles. Touted as an affordable alternative to taxis, the concept is gaining popularity in major cities.

Still, not everyone is on board.

Citing safety and fairness concerns, several government agencies have ordered such companies to stop operating. Others are creating stricter regulations.

While Lyft is only testing the market in the area at this time, the PTC reached out to it first, Jackson said, to ensure it understands the requirements of operating in Hillsborough County.

As it stands, Lyft doesn't seem to fall into those parameters.

"If someone is planning to do this on the weekend as a side job and just wants to use their mom's car, that's not how it's set up here," Jackson said.

Unique in Florida, the PTC was created by the Florida Legislature to regulate vehicles-for-hire in Hillsborough — taxicabs, limousines, vans, basic life support ambulances and tow trucks.

To operate a taxi here, several steps are required.

Companies have to apply for and be licensed by the PTC. Each vehicle in the fleet must pass an inspection and be permitted, of which there is a limited number available. Plus, drivers have to pass a background check and take a training course. The agency also sets minimum and maximum fare rates for taxis and premium services such as limos.

That last rule proved problematic for a company called Uber in 2012 when it brought its premium service to Tampa for the Republican National Convention.

"Uber wanted to use executive cars and limos and run them like taxicabs," said PTC Chairman and Hillsborough County Commissioner Victor Crist. "In our market we separate the two. Uber wanted to create something new."

The PTC set Uber's minimum fare to match limos at $50, which was three times as pricey as the service's minimum fare in New York City, London or Paris — causing uproar from customers on social media.

Uber, which also operates a service similar to Lyft called UberX, said then that its experience with the PTC had dissuaded it from coming back here again.

But there's reason to have strict rules in place, Crist said.

"As a result, we have the most professional, cleanest and safest delivery and public transit services found anywhere in the world and we're proud of that fact," Crist said.

That doesn't mean there's not room for change.

"I would never say they can't make it here but it would require some tweaking of our rules and how they do business," Jackson said.

The PTC regularly reviews its regulations, Crist said.

"We want new businesses but we also want to make sure our standards are maintained so that when you get in that vehicle it's safe," Crist said.

On its website, Lyft highlights the importance of safety for drivers and passengers.

Among its policies — which Lyft says it checks — drivers can't have any violations in the last seven years for drinking and driving, no sexual offenses or felonies and must have personal auto insurance that meets state guidelines. Vehicles must be model year 2000 or newer and pass a safety inspection.

Advertisements on Facebook call for Tampa drivers interested in earning up to $20 an hour, but a spokeswoman for Lyft said there are no firm plans to expand to the area.

"We are currently testing ads in 20 cities where Lyft is not operating but that we are interested in exploring," Paige Thelen said in an email. "While Tampa would be a great city for Lyft, we have not made any plans to launch there at this time."

Brian Seel, one of the founders of the Connect Tampa Bay transportation group, said he assumes Lyft will have a hard time breaking into the area but is interested in seeing what happens.

"We've got to be more willing to think outside the box and embrace new ideas," Seel said. "Even if Lyft doesn't work out, the system we have of basically just roads and an overwhelmed bus system just isn't cutting it."